CAJ | 학술논문

钻井过程中钻具经常会因扭矩过大而“憋停”，当扭矩达到某一值后钻具会突然快速释放，这种现象通常称为钻具粘滑。钻具的粘滑经常伴随井下震动，容易引发金刚石钻头崩齿，从而缩短钻头寿命，也会引起井下仪器（MWD/LWD）失效。钻具的粘滑跟井下钻具组合和所钻地层岩性有关。粘滑现象是一种阂值现象，即低于临界转速粘滑就会发生。软扭矩系统针对粘滑现象作用机理而研发，通过降低临界转速，有效地控制了钻具粘滑。该系统在长北气田进行了推广应用，从源头上消除了钻具粘滑现象，保护了钻头和井下仪器，应用效果良好。
찬정과정중찬구경상회인뉴구과대이“별정”，당뉴구체도모일치후찬구회돌연쾌속석방，저충현상통상칭위찬구점활。찬구적점활경상반수정하진동，용역인발금강석찬두붕치，종이축단찬두수명，야회인기정하의기（MWD/LWD）실효。찬구적점활근정하찬구조합화소찬지층암성유관。점활현상시일충애치현상，즉저우림계전속점활취회발생。연뉴구계통침대점활현상작용궤리이연발，통과강저림계전속，유효지공제료찬구점활。해계통재장북기전진행료추엄응용，종원두상소제료찬구점활현상，보호료찬두화정하의기，응용효과량호。
Drilling string will be stopped rotation due to over-torque while drilling, and drilling string will be released suddenly when the torque reached the peak torque, this phenomenon is be called drilling string stick-slip. Drilling string is vibrating while stick-slip occurring, and results in teeth of PDC bit broken easily, so shorten bit life, and leads to down hole MWD/LWD lost signal. Drilling string stick-slip is related with BHA and formation. Stick-slip is one kind of threshold phenomenon, so will be happened when drilling string rotary speed lower critical rotary speed. Soft torque system is studied special for preventing stick-slip phenomenon through decrease critical rotary speed. This system has be applied in Changbei gas field widely and avoid drilling string stick-slip phenomenon, protect bit and down hole instruments. The application result is very effectieve.